Porosity and Water Permeability Study of Supercritically Carbonated Cement Pastes Involving Mineral Additions
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- 作者：Carlos A. Garcí ; a-Gonzá ; lez ; Ana Hidalgo ; Julio Fraile ; Ana M. Ló ; pez-Periago ; Carmen Andrade ; Concepció ; n Domingo
- 刊名：Industrial & Engineering Chemistry Research
- 出版年：2007
- 出版时间：April 11, 2007
- 年：2007
- 卷：46
- 期：8
- 页码：2488 - 2496
- 全文大小：535K
- 年卷期：v.46,no.8(April 11, 2007)
- ISSN：1520-5045
文摘
The objective of this ongoing work is to improve the physical properties of Portland cement pastes andPortland-composite cement pastes containing silica fume and/or fly ash through an accelerated carbonationprocess based on the use of SCCO2. Cement carbonation allows the preparation of cementitious compositesreinforced with low-cost alkali-intolerant products and the use of these materials in solidification/stabilizationof hazardous waste. In the supercritical treatment, results suggested that the carbonation rate of the portlanditephase slowed down after the first reaction stage and was overtaken by the reaction rate of the CSH andettringite phases. Samples carbonated under the supercritical conditions developed a higher volume of gelpores than those obtained by natural carbonation. The microstructural analysis was completed by analyzingthe water permeability of a cement paste/sand composite (mortar) after supercritical carbonation. Obtainedvalues showed that supercritical carbonation reduced water permeability significantly.